Abstract: Objective The research project reported in this paper was designed to study the epidemio logical characteristics of measles in Baoji city in order to forecast its epidemic trend，establish interventions of prevention＆treatment，and reduce its morbidity. Methods Statistical analysis was conducted on the data of measles recorded from the year l990 to 2003 in Baoji city ELISA was used to detect IgG anti body against measles in serum.Results It was found that periodic ombreaks of measles were apparent in baoji city. The number of cases reported from January to July acconntad for 86.22％of the total of the year，with an epidemic circle of 3-5 years. There were both sporadic epidemic and dramatic outbreaks of the disease，with the former being dominant. From the age dstribution of cases in different times，it was seen that the age at which the disease developed was postoned.The vaccination rate weighed in 2002 and 2003 was 98.21％. The positive rate of antibody in population was 85.5％ with a protection rate of 77.42％. Conclusion There was a false high rate of measles inocculation in Baoji city. A lower protection rate means a tendency of high incidence. Thus comprehensive intervention of prevention and control should be taken，including enhancing routine vaccination continuously，improving the effective inouclation rate of measles vaccine，promoting booster vaccination of measles properly in relative high aged population in the whole city，reinforcing surveillance and analysis of epidemic situation and taking emergency actions timely in epidemic spots to avind severe outbreaks of peidemic.